Man! My life has been a blur the last 2 week! A few things before I start:

  1. I’m unaccustomed to writing math-centered posts (which you’ve noticed if you read anything prior to the Mullet Ratio). Though I’m still pretty green, I’m thrilled to be involved in the “mathblogosphere”, for which, there must be a better name.
  2. The Barbie Bungee lesson was planned in way less time than the Mullet Lesson, which was in the works for weeks. I was saving pictures, constructing the worksheets, planning my own mullet since April, and it still makes me a little embarrassed to know that people are downloading it. I would have changed this color, updated that picture, or tweaked this font. And the Barbie Bungee lesson was largely planned the morning of. Polished and perfect, it’s not.
  3. In the last week, I got a few thousand hits on the Mullet Lesson, a few dozen tweets about it from people I’ve never met, and it’s been taught in Orange County, the Netherlands, and maybe some places in between. Plus, I got tagged to teach an iPad class with digital textbooks next year and I finished BTSA. Now I’m writing this post, finally. Again, polished and perfect, it’s not.

So, like a proctologist about to scope, I ask that you keep #2 in mind. Remember that teaching and learning are both about improvement over time, and this lesson will likely improve.


Saturday, for the TEAMS grant at UC-Riverside, a couple teachers talked about Barbie Bungee and I figured I could call the ante and raise the stakes. I sketched some schematics for a bungee platform and began testing prototypes a few days before the Bungee lesson (Thursday/Friday). I finished up building 9 more of them last night.

It’s not too hard. It’s exactly how it looks. Those angles are 45 degrees and each one hooked onto the chain-link fence outside my class so students could raise and lower the platform to various heights.

Students’ only homework this week was for their group to bring in a doll. I advised them on size, weight, and clothing (one student gel-painted a bikini because she couldn’t find Barbie’s shirt), and stored them in class, tagged by period.

Late last night, I wondered in a panic, “Do I have enough content to fill the 90 minutes for two days?”

I turned to my teaching advisor, Google. It turns out I’m nowhere near the first teacher (as I found out via Twitter) to try a Barbie Bungee lesson.

…and many of them more epic than my plan.

NCTM’s Illuminations had some good questions for students.
The Math Lab obviously planned their blog post, with pictures and stuff.
Mr. Pederson filmed his class doing the bungee off the bleachers.
Fawn Nguyen has been doing it for years, and even planned hers for the same day as me! Talk about being born under the same geeky star! I hope someday my Barbie Bungee lesson will be as involved and pointed as hers. You nailed it, Fawn! Fabulous work.

Seriously, teachers. If you’re interested in this lesson, go to her page first. I guarantee it’s worth your time.

Day 1

After the warm-up, announcements, and whatever, I show these two videos:

Purists will note that the second video (a Russian Missile silo) isn’t technically bungee jumping; they’re using what rock climbers call static rope, which doesn’t stretch. Meaning that they fall about 15-20 meters and are yanked at the bottom. Russians have a different meaning for fun, I suppose.

This is the front row at a KISS concert in Moscow.

But back to Barbies.

I started a discussion first (low-entry point, everybody’s involved).

What do you think the world’s first bungee jumpers thought about?
What makes a bungee jump exciting?
What are the dangers in a bungee jump?

I framed our plan for the day, passed out the pink papers (attached below) and set them to work.

This part was pretty easy. They began building bungee cords, threading their platforms and heading outside to bunge. The GATE (Honors) students finished fairly quickly, some even wanting to go higher (which I saved for day 2).

Memorable quotes:

“What if they don’t hit the ground on the first try?”
“It’s okay to smash their face a little bit, right?”

And my favorite:
“Can I tape her dress down? She’s flashing the goodies with every jump.”

Day 2:

Students were notified that Barbie was to jump 203 centimeters today.

Before we go further, here’s what yesterday’s pink worksheet looked like (Attachment below):

Mathematicians, you’ll note that this is a good time to talk about Ceiling Functions (because you can’t have a 6.3 rubber bands), but I glossed over that for this year.

Students, predictably, added the 60 cm to the 140 cm “then added a little more” to plan for the 203 cm jump. Okay, fine.

Then we took them outside to video as the Barbies jumped 203 cm.

Some classes were very successful, pushing the limits of how close they could get. (and getting frustrated when their doll’s skull cracked the ground).

Not all jumps were successful.

Then, back inside to answer questions on the back and make calculations for the roof jump.

The janitor had agreed earlier to climb up to the roof and toss the dolls off, two at a time. Of course, I had to build a separate launching platform for the Pavilion roof.

I must really love my job, because I hate drilling pilot holes.

We also taped two yardsticks to the wall, so we could play back the footage and see who “won”. For the more cautious classes, it wasn’t really necessary. Here are all the jumps put together.

Stuff I changed on the fly:

  • Bundle the rubber bands in 20s, then make sure to get all 20 back. (Way easier than counting each group.)
  • Show that the 60 cm jump is the distance downfrom the ledge, not up to the fence.
  • For heavy dolls, double up the bungee
  • Go very slowly to show the class a slipknot for Barbie’s legs.

All told, it was an excellent activity, but not yet a great lesson. Check out Fawn’s post on this. It’s awesome. Mine can get close, but for now it’s just a good year-end activity.

Download the Barbie Bungee Doc.

~Mr. V